Refrigerant recovery system with flush mode and associated flushing adapter apparatus

ABSTRACT

A refrigerant recovery system is operative in a recovery mode to recover refrigerant from an air conditioning circuit, and in a cleaning mode to cleanse the recovered refrigerant of impurities therein. In the recovery mode the refrigerant is withdrawn from the air conditioning circuit and flowed through a filter dryer by a compressor which then forces the refrigerant through a condenser into a storage container. In the cleaning mode, liquid refrigerant from within the storage container is continuously flowed through the filter dryer and then back into the storage container. To remove impurities from within the air conditioning circuit, the recovery system is also operative in a closed loop flushing mode in which liquid refrigerant from within the storage container is continuously pumped through a portion of the air conditioning circuit, filtered, and then returned to the storage container without any appreciable quantity of refrigerant being vented to atmosphere during the flushing process. For use in conjunction with its flushing mode of operation, the recovery system is provided with a specially designed flushing adapter kit having removable adapter fittings configured to precisely mate with inlet and outlet fittings of the particular air conditioning circuit to be tested. In another embodiment thereof, the kit is provided with removable adapter fittings of a universal configuration permitting the recovery system to be operatively connected to various types of air conditioning circuits.

CROSS-REFERENCE TO RELATED APPLICATION

This is a division of application Ser. No. 715,429, filed Jun. 14, 1991,now U.S. Pat. No. 5,168,720, is a continuation-in-part of U.S.application Ser. No. 588,561 filed on Sep. 26, 1990 now U.S. Pat. No.5,117,641 and entitled "Refrigerant Recovery System With Flush Mode".

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates in general to devices for recovering refrigerantfrom air conditioning systems, and in particular to a device which willalso flush the air conditioning system of impurities.

2. Description of the Prior Art

Air conditioning systems such as in vehicles utilize a refrigerant thatscientists believe is harmful to the Earth's atmosphere. In the past,when working on an air conditioning system, often the worker would ventthe existing refrigerant to atmosphere. Now, these environmentalconcerns and resulting regulations are requiring many workers to recoverthe refrigerant, clean it and reuse it.

Prior art refrigerant recovery systems generally utilize an accumulatorfor trapping oil and liquid refrigerant, a filter dryer for removingmoisture and impurities, and a compressor for compressing the gaseousrefrigerant into high pressure gaseous refrigerant. A condensercondenses the gaseous refrigerant into liquid refrigerant, which is thenplaced into a storage container.

It is also known in the prior art to have a cleaning cycle. In thecleaning cycle, the refrigerant will be recirculated out of the storagecontainer, through the recovery apparatus for further filtering andcleaning, then placed back into the storage container.

While these systems will withdraw and clean refrigerant adequately,often, there will be a need to flush the air conditioning system.Because of the failure in the air conditioning system, there may bemetal parts, powders and sludge located in the components of the airconditioning system. In the prior art, the worker will discharge anaerosol flush through the air conditioning system. This aerosol flushalso utilizes a refrigerant chemical, however. The aerosol flush wouldbe vented to the atmosphere, which could be harmful.

SUMMARY OF THE INVENTION

The present invention provides improved apparatus for recoveringrefrigerant from an air conditioning system. In a representativeembodiment thereof, the recovery apparatus includes storage containermeans for receiving refrigerant, filter means for receiving andfiltering refrigerant, and recovery means for flowing refrigerant fromthe air conditioning system, through the filter means and into thestorage container means. Cleaning means are provided for cleansing therecovered refrigerant of impurities by sequentially flowing it out ofthe storage container means, through the filter means and back into thestorage container means.

According to a key feature of the present invention, the recoveryapparatus is provided with closed loop flushing means which areremovably connectable to a pair of air conditioning system inlet andoutlet fittings and are selectively operable to withdraw flushingrefrigerant from the storage container means, force the withdrawnflushing refrigerant through a portion of the air conditioning system toflush impurities therefrom, and then return the flushing refrigerant tothe storage container means without venting any appreciable amount ofrefrigerant to atmosphere.

In accordance with another aspect of the present invention, adaptermeans are provided for removably connecting the closed loop flushingmeans to the air conditioning system inlet and outlet fittings. In oneembodiment thereof, the adapter means include a plurality of adapterfittings having first portions removably connectable to flushing conduitportions of the flushing system, and second portions configured toprecisely mate with the inlet and outlet fittings in place with the airconditioning system connection fittings temporarily removed therefrom.

These removable adapter fittings may be furnished as a "specific" setwhich permits the flushing portion of the recovery apparatus to beconnected to the various refrigerant inlet and outlet fittings of an airconditioning system made by a particular manufacturer. Alternatively,the adapter fittings may be furnished in a "master" set which includes arelatively large number of adapter fittings each configured to preciselyfit a refrigerant flow fitting on a particular brand of air conditioningsystem.

According to another feature of the present invention, a flushing systemadapter fitting is provided with a specially designed "universal"configuration which permits it to be operatively connected to a widevariety of refrigerant flow fittings of the general type having an openouter end, and a transversely enlarged outer side portion positionedinwardly of the open outer end.

In a preferred embodiment thereof, this universal adapter fittingincludes a hollow body extending along an axis and having a first endportion operatively and removably connectable to a flushing conduit orhose, and a resilient hollow second end portion insertable plug-likeinto the open outer end of the refrigerant flow fitting. First andsecond arm means are pivotally carried on the hollow body for axialmovement along its length and have outer end portions positionableinwardly of the transversely enlarged outer side portion of therefrigerant flow fitting on generally opposite sides of the flowfitting. Means are provided for creating relative axial movement betweenthe hollow adapter fitting body and the first and second arm means in amanner releasably locking the outer are means end portions against thetransversely enlarged outer side portion of the refrigerant flow fittingand forcibly wedging the resilient second end portion the hollow adapterfitting body into the open end portion the refrigerant flow fitting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a recovery apparatusconstructed in accordance with this invention;

FIG. 2 (Prior Art) is a schematic diagram of a representativeconventional air conditioning system with which the recovery apparatusmay be utilized;

FIG. 3 is a schematic diagram of a flushing adapter kit embodyingprinciples of this invention and being used to representatively connectthe recovery apparatus to a condenser portion of the air conditioningsystem of FIG. 2;

FIG. 4 is an enlarged scale exploded side elevational view of an outerhose end portion of the adapter kit illustrating its connection to theoutlet fitting of the condenser using a specially designed removableadapter fitting;

FIGS. 4A and 4B are side elevational views of two representativealternate embodiments of the adapter fitting shown in FIG. 4;

FIG. 5 is a simplified side elevational view of a third alternateembodiment of the adapter fitting;

FIG. 6 is an enlarged scale perspective view of a fourth alternateembodiment of the adapter fitting; and

FIG. 7 is a reduced scale side elevational view of the FIG. 6 adapterfitting operatively connected to the outlet fitting of the condensershown in FIG. 4.

DETAILED DESCRIPTION

Referring initially to FIG. 1, recovery apparatus or system 11 mayutilize a manifold 13. Manifold 13 has a high side connection 15 and alow side connection 17. The connections 15,17 connect to hoses (notshown) which lead to the high and low sides, respectively, of an airconditioning system (not shown). An intake hose 19 will lead frommanifold 13 to an intake line 2 of the recovery apparatus 11.

Intake line 21 has an intake valve 23, which is solenoid actuated toopen and close the intake line 21. The refrigerant will flow through theintake line 21, as indicated by the arrow, to an accumulator 25.Accumulator 25 will trap any liquid refrigerant flowing through theintake line 21, as well as trapping oil contained in the airconditioning system. After recovery, an oil drain valve 27 allows theoil to be drained and measured so that the worker will know how much oilwas withdrawn from the air conditioning system. .Liquid refrigerantcontained in the accumulator 25 will boil off into a gas and flow out anaccumulator output line 29. An electric heater (not shown) in theaccumulator 25 assists in converting liquid refrigerant into gas.

A check valve 31 locates in the accumulator output line 29 to assureflow is only in the direction of the arrow. The accumulator output line29 leads to a conventional filter dryer 33. Filter dryer 33 will filterthe refrigerant of impurities and water moisture. The refrigerant in thefilter dryer 33 will be in a gaseous phase. Filter dryer 33 has anoutput line 35 that leads to a compressor input line 37. A compressorintake valve 39 is solenoid actuated, and will selectively open andclose the compressor input line 37. The compressor input line 37 leadsto a conventional compressor 41 of a type that will compress a gaseousrefrigerant.

Compressor 41 has an output 43 through which high pressure, hot gaseousrefrigerant will be discharged. The output 43 leads to an oil separator45, which is conventional, and may be considered a part of compressor41. Oil separator 45 will separate oil contained in the refrigerantbeing discharged from the compressor 41. The oil in the oil separator 45will be returned to the compressor 41 in a conventional manner.

The oil separator 45 connects to a conventional condenser 47. Condenser47 is a heat exchanger which will have a fan for flowing through finnedtubes. The gaseous refrigerant will be cooled by the condenser 47. Thiscooling results in the gaseous refrigerant converting into a liquidrefrigerant at the output line 49.

The condenser output line 49 connects into a storage input line 51. Thefilter dryer output line 35 also connects to this storage input line 51in a "T" connection. One leg of the T connection connects to thecompressor input line 37, while the other leg of the T connectionconnects to the storage input line 51. A check valve 53 in storage inputline 51 assures flow only in a direction away from compressor 41.

A high pressure switch 55 will monitor the pressure in the storage inputline 51. If it exceeds a maximum set amount, then the high pressureswitch 55 will turn off the compressor 41. A conventional sight glass 57in the storage input line 51 enables a worker to visibly determine ifgas bubbles are present within the liquid refrigerant in the storageinput line 51. The storage input line 51 has an end which will connectto a storage intake hose 59. A high pressure gauge 61 provides anindication of pressure in the storage input line 51.

The storage intake hose 59 will connect to a storage container 63.Storage container 63 is a tank for receiving the liquid refrigerant fromthe storage input line 51. Storage container 63 preferably has means(not shown) for indicating when the storage container 63 becomes 80percent full.

A storage withdrawal hose 65 connects to a fitting which extends to thebottom of the storage container 63. The storage withdrawal hose 65 willconnect to a storage withdrawal line 67. Line 67 leads to the input sideof a liquid pump 69. Liquid pump 69 is designed for pumping liquids,preferably at a rate of about 58 gallons per hour.

Liquid pump 69 has an output connected to a flush line 71. A clean/flushvalve 73 connects into the flush line 71 for allowing fluid to continuepassing through the flush line 71, during a flushing mode, or fordirecting the liquid refrigerant to a recirculation line 75 for acleaning mode. The recirculation line 75 has a solenoid valve 77 thatwhen actuated will selectively open and close the recirculation line 75.The recirculation line 75 connects to the accumulator output line 29 forrecirculating liquid refrigerant back into the filter dryer 33.

The end of the flush line 71 is adapted to be connected to a flush hose79 which forms a portion of a specially designed flushing adapter kit 80used to temporarily connect the recovery system 11 to the airconditioning system, for flushing purposes, as subsequently describedherein. When in the flush mode, the valve 73 will direct liquidrefrigerant to the flush hose 79. The flush hose 79 connects to an inputport in the air conditioning system. A return hose 81, also part Of theflushing adapter kit 80, connects to an output port in the airconditioning system. This enables the flushing liquid refrigerant toreturn from the air conditioning system to the return hose 81. Returnhose 81 has a recovery branch hose 82 which is adapted to connect to theintake line 21 after flushing and when the manifold line 19 is removed.

A filter 83 connects in the return hose 81 as subsequently described andis operative to filter liquid refrigerant being flushed through the airconditioning system. Filter 83 is much smaller than filter dryer 33, buthas a much lower pressure drop. Consequently, liquid refrigerant can beefficiently pumped through the filter 83 at a much higher rate thanthrough filter dryer 33.

A check valve 85 downstream of filter 83 assures that the flow throughthe return hose 81 will only be in a returning direction. The checkvalve 85 is located in a return line 87. The return line 87 connects tothe storage input line 51. The return line 87 will bypass theaccumulator 25, filter dryer 33 and compressor 41.

In the recovery operation, the hose 19 will be connected to the manifold13. Hoses (not shown) from the high and low side of the air conditioningsystem will be connected to the high and low side connections 15 and 17,respectively, of the manifold 13. Valves 23 and 39 will be open. Valve77 will be closed. Pump 69 will not be operating. Compressor 41 will beturned on.

Refrigerant will flow from both the high and low side of the airconditioning system to the recovery apparatus 11. This refrigerant willbe a mixture of liquid and gas, and it will flow through the intake hose19 to the intake line 21. The accumulator 25 will separate oil from therefrigerant. Any liquid components in the refrigerant will be trapped,and will eventually boil off into a gas.

The refrigerant as a gas flows out the accumulator output line 29 andthrough the filter dryer 33. Moisture and impurities will be filtered bythe filter dryer 33. The refrigerant will flow through the compressorinput line 37 into compressor 41. Compressor 41 compresses therefrigerant to a high pressure, hot gas.

The high pressure gaseous refrigerant flows through oil separator 45into condenser 47. Condenser 47 will condense the gaseous refrigerantinto a high pressure liquid refrigerant. This refrigerant will flowthrough the storage input line 51 and the storage intake hose 59 intothe storage container 63. The worker will continue withdrawingrefrigerant until a selected level of vacuum has been achieved, assuringwithdrawal of substantially all of the refrigerant from the airconditioning system.

Then, the worker will clean the refrigerant more thoroughly so that itcan be reused or used for flushing. In the cleaning mode, the compressor41 will be turned off. The valves 23 and 39 will be closed. The valve 73will be moved to a position to direct refrigerant to recirculation line75. Valve 77 will be open. Pump 69 will be turned on.

Pump 69 will withdraw liquid refrigerant from the storage container 63,through withdrawal line 67 into the pump 69. The pump 69 pumps theliquid refrigerant out line 71. The valve 73 will direct the liquidrefrigerant through line 75 and back in through the filter dryer 33. Thefilter dryer 33 will further clean the refrigerant. The refrigerant willflow out the filter dryer output line 35 and back into the storage inputline 51. The solenoid valve 39 will prevent any of this liquid fromflowing into the compressor input line 37. The refrigerant will flowthrough the storage input line 51 back into the storage container 63.The worker will continue this recirculation process until enough cycleshave assured that the refrigerant is completely clean. One specificationrequires about 15 minutes of recirculation.

Then, the worker may wish to flush the air conditioning system ofimpurities. The worker will disconnect the hoses leading from the airconditioning system to the manifold connections 15,17. He will connectthe flushing adapter kit hoses 79,81 to the same ports in the airconditioning system as subsequently described. He will connect the hose82 to the intake line 21. The storage container 63 will need a quantityof clean liquid refrigerant that is approximately ten times the volumeof the refrigerant recovered from the air conditioning system.

In the flush mode, valves 23 and 39 remain closed. Valve 77 will beclosed. Valve 73 will be switched to the other position, blocking flowinto the recirculation line 75. Liquid pump 69 will be turned on.

Liquid pump 69 will withdraw liquid refrigerant from the storagecontainer 63. The liquid pump 69 discharges the liquid refrigerantthrough the flush line 71 into the flush hose 79 and into the airconditioning system. The liquid refrigerant will flow through the airconditioning system, cleaning it of impurities. This liquid refrigerantwill return through the return hose 81 to the return line 87.

As the liquid refrigerant flows into the return line 87, it will passthrough the filter 83. The filter 83 will separate the impuritiescollected during the flushing mode. The liquid refrigerant in the returnline 87 will flow directly to the storage input line 51 and from thereinto the storage container 63. In the flushing mode, the filter dryer 33is bypassed, as well as the accumulator 25 and compressor 41.

After cycling through the flush mode for a selected duration, the workerswitches back to the recovery mode. The pump 69 will be turned off.Valve 77 closes and valves 23 and 39 open. The compressor 41 turns on.The flushing refrigerant will be withdrawn from the air conditioningsystem through hoses 8 and 82. It will pass through intake line 21,accumulator 25, filter dryer 33, compressor 41, condenser 47 and intothe storage container 63 in the manner described above.

The worker will then switch the recovery apparatus 11 back to the cleanmode. The filter 83 may not be sufficient to completely clean theflushing refrigerant to specifications. He will repeat the cleaningcycle described above to clean the refrigerant in the storage container63.

The recovery system 11 has significant advantages. It enables the workerto flush the air conditioning system of impurities with no additionalflushing fluid being required. The refrigerant collected can be usedalso for the flushing. This avoids requiring an aerosol flush, whichresults in venting of harmful materials to the atmosphere.

The Flushing Adapter Kit 80

Schematically illustrated in FIG. 2 (Prior Art) is a representative airconditioning system or circuit 91, of conventional construction, withwhich the recovery system 11 may be utilized. For purposes ofillustration, air conditioning system 91 is shown as being an automotivesystem, such as those installed in cars and trucks, but could be ofanother type such those used in residential and commercial buildings.Air conditioning system 91 has a compressor 93 with inlet and outletfittings 95,97; an evaporator 99 having inlet and outlet fittings101,103; an expansion valve 105; and a condenser 107 having inlet andoutlet fittings 109,111.

These four components of the air conditioning system 91 are operativelyinterconnected by system conduit means including a conduit 113, aconduit 115, and a conduit 117 in which the expansion valve 105 isremovably interposed. First ends of the conduits 113,115 are secured toa block-type connection fitting 119 removably attached to the inlet andoutlet fittings 95,97 of compressor 93, and the opposite ends ©fconduits 113,115 are secured to connection fittings 121,123 removablyattached to the evaporator outlet fitting 103 and the condenser inletfitting 109, respectively. One end of conduit 117 is secured to aconnection fitting 125 removably attached to the condenser outletfitting 111, and the other end of conduit 117 is secured to a connectionfitting 127 removably attached to the evaporator inlet fitting 101.

Turning now to FIG. 3, the flushing adapter kit 80 includes the flushinghoses 79 and 81, the filter 83, a sight glass 129, a Schrader tee 131and a strainer 133. The filter 83, sight glass 129, tee 131 and strainer133 are removably connected in hose 81 in the arrangement shown in FIG.3. Specially designed adapter fittings 133,135 are removably secured tothe outer or right ends of the flushing hoses 79 and 81, respectively.

To ready the condenser 107 for flushing, the conduit connection fittings123,125 are respectively removed from the condenser inlet and outletfittings 109 and 111 (as illustrated in phantom in FIG. 3), and theadapter fittings 133,135 are attached to the fittings 109,111 in placeof the removed connection fittings 123,125.

According to a feature of the present invention, the adapter fittings133,135 are configured to precisely mate with the condenser inlet andoutlet fittings on a particular brand of automotive vehicle airconditioning system, or other type of air conditioning system. To thisend, the adapter fittings 133,135 are given configurations substantiallysimilar to those of the removed connection fittings 123,125. As anillustration, it will be assumed that the condenser outlet fitting 111is a male flare fitting portion, as depicted in FIG. 4, having a tubularbody portion 137 with a male flare section 139 at its upper end. Anexternally threaded, hollow tubular fastening stud 141, having ahexagonal head portion 142, is slidably and captively retained on bodyportion 137.

The illustrated adapter fitting 135 (like its companion adapter fitting133) is accordingly configured as the female half of a flare fitting,having a tubular body 143 with a female flare section 145 formed on itslower end, and a fastening nut 147 slidably and captively retained onbody 143. To connect the adapter fitting 135 to the outlet fitting, thefemale flare section 145 is placed over the male flare section 139, andthe stud and nut 141,147 are tightened together. To removably connect itto its associated flushing hose 81, the adapter fitting 135 is providedat its upper end with a reduced diameter, externally threaded portion149 which is threadable into a coupler fitting 81_(a) on the outer endof hose 81.

The adapter fittings 133,135 are thus configured to precisely mate withthe inlet and outlet fittings of the air conditioning circuit portion(for example, the condenser) of a particular size, type and/or brand ofair conditioning system with which they are to be used in conducting aflushing operation. For differently configured inlet and outlet fittingsthe adapter fittings can, of course, be configured differently.

For example, if the representative condenser fitting 111 was configuredas the female portion of an O-ring pressure fitting, the alternateadapter fitting 135_(a) shown in FIG. 4A would be given the generalconfiguration of the complementary male section of such outlet fitting.Specifically, the adapter fitting 135_(a) has a tubular body 151 with anexternal sealing flange 153 formed on its lower end, a fastening nut 155slidably and captively retained on body 151, and the externally threadedupper end portion 149 removably connectable to the coupling fitting81_(a) on the flushing hose 81.

As another example, when necessary, the adapter fitting 135 could beconfigured as a barb fitting 135_(b) as illustrated in FIG. 4B, barbfitting 135_(b) having a tubular body 157 upon which a plurality ofexternal annular barb portions 159 are formed, and the threaded upperend portion 149 for removably connecting the adapter fitting 135_(b) tothe coupler fitting 81_(b).

To provide for flushing of the compressor 93 (FIG. 2), a block typeadapter fitting 135_(c) may be provided as illustrated in simplifiedfashion in FIG. 5. Adapter fitting 135_(c) has a block-shaped body 161;a pair of openings 95_(a),97_(a) on its bottom side for receiving thecompressor inlet and outlet fittings 95 and 97; a pair of the externallythreaded portions 149 formed on its top side for removably connectingthe body 161 to the coupling fittings 79_(a),81_(a) of the flushinghoses 79 and 81; and a bolt 163 for operatively securing the body 161 tothe compressor.

A variety of removable adapter fittings may be furnished as a portion ofthe flushing adapter kit 80 schematically depicted in FIG. 3. Forexample, a "specific" adapter fitting set may be provided to permit thekit to be used in conjunction with the automotive air conditioningsystems of a particular car or truck manufacturer, the specific adapterfitting set including a variety of adapter fittings connectable to thecompressor, evaporator or condenser portion of the selected type of airconditioning system line.

Alternatively, a "master" set of adapter fittings may be provided topermit flushing connection to the compressor, evaporator or condenserportions of air conditioning systems produced by a selected variety ofdifferent manufacturers.

The representative adapter fittings 135, 135_(a) and 135_(c) describedabove have predetermined configurations which permit each of them to beprecisely mated with a specific refrigerant fitting on a particular airconditioning system or circuit. The present invention, however,additionally provides an adapter fitting 135_(d) (FIG. 6) which has a"universal" configuration permitting it to be removably connected to avariety of air conditioning circuit inlet and outlet fittings.

Adapter fitting 135_(d) includes an elongated, externally threaded,hollow tubular body 165 having an enlarged hexagonal right end portion167. A hollow, generally frustroconically shaped resilient plug fitting169 is coaxially secured to the left end of the body 165 for purposeslater described. To removably connect the adapter fitting 135_(d) to,for example, the flushing hose 81, an externally threaded, hollowtubular portion 149 (similar to the portions 149 on the adapter fittingspreviously described herein) projects outwardly from the hexagonal end167 and is threadably into the hose coupling 81a.

Threaded onto the body 165 is a hollow cylindrical adjustment member 173having a knurled right end portion 175 immediately adjacent an annulargroove 177 formed around the outer side of the adjustment member. Theoutwardly bent central portions of a pair of elongated bar members 179,extending transversely to the body 165, are slidably received andretained within the groove 177, with facing outer ends of the bars 179being fixedly secured to one another with hollow rivet members 181.

Right end portions 183 of a pair of leftwardly projecting locking bars185 are positioned as shown between opposite end portions of the bars179. The bar end portions 183 are pivotally connected to the bars 179 bya pair of pivot pins 187 extended through aligned circular openings (notshown) in the associated bar ends 179,183 and releasably retained inplace by removable cotter pins 189 installed in the opposite ends ofeach of the pivot pins 187. Pivot pins 187 permit each of the lockingbars 185 to pivot relative to the bars 179, about parallel axestransverse to the axis of body 165, as indicated by the double-endedarrows 191 in FIG. 6.

The lengths through which the locking bars 185 leftwardly project beyondthe bars 179 may be selectively increased by removing the pivot pins187, moving bars 185 to the left, and reinstalling the pivot pinsthrough circular holes 193 formed in the right ends of bars 185. Forpurposes later described, a pair of generally circular locking tabmembers 195, having recesses 197 formed in facing side edge portionsthereof, are transversely to the left ends of bars 185 and projectlaterally inwardly therefrom.

To provide connection clearance for the adapter fitting 135_(d), facingside edge portions of the bars 185 adjacent the tabs 195 are inset as at199. As indicated by the double-ended arrow 201 in FIG. 6, by rotatingthe adjustment member 173 in an appropriate direction relative to thebody 165 the member 173 (and thus the bars 179 and 185) may be movedleftwardly or rightwardly along the body 165.

Referring now to FIG. 7, the connection of the universal adapter fitting135_(d) to the representative condenser outlet fitting 111 will now bedescribed. To make this connection, the hollow resilient cone plug 169is inserted into the male flare section 139 of the outlet fitting 111.The locking bars 185 are then pivoted inwardly to position the lockingtabs 195 against opposite sides of fitting 111 beneath the stud head 142which defines a transversely enlarged shoulder portion of the fitting111.

With the tabs 195 held against the opposite sides of the fitting 111,the adjustment member 173 is rotated to force the fitting bodydownwardly as indicated by arrow 203. This downward movement of body 165upwardly draws the tabs 195 firmly against the underside of the studhead 142 and wedges the resilient cone 169 into the fitting section 139,thereby releasably locking the adapter fitting 135_(d) to the outletfitting 111 and forming an exterior compression seal between the cone169 and the fitting section 139.

Adapter fitting 135_(d) can also be releasably locked and sealed in thismanner to a variety of other air conditioning system refrigerant inletand outlet fittings as well. For example, the tabs 195 can be releasablylocked against the attachment stud head portion of an O-ring compressiontype inlet or outlet fitting, or against one of the annular barbportions of a barb type inlet or outlet fitting, the tab recesses 197facilitating this locking connection to the typically smaller annularbarbs.

The foregoing detailed description is to be clearly understood as beinggiven by way of illustration and example only, the spirit and scope ofthe present invention being limited solely by the appended claims.

What is claimed is:
 1. An adapter fitting for operatively and removablyconnecting an end of a refrigerant transfer conduit to a refrigerantflow fitting on an air conditioning circuit, said refrigerant flowfitting having an open outer end and a transversely enlarged outer sideportion spaced inwardly apart from said open outer end, said adapterfitting comprising:a hollow body extending along an axis and having afirst end portion operatively and removably connectable to said end ofsaid refrigerant transfer conduit, and a resilient hollow second endportion insertable plug-like into said open outer end of saidrefrigerant flow fitting, said hollow body having a generally tubularconfiguration and being externally threaded; first and second arm meanshaving outer end portions positionable inwardly of the transverselyenlarged outer side section of said refrigerant flow fitting ongenerally opposite sides thereof, and inner end portions; a hollowcylindrical adjustment member threaded onto said hollow body and beingrotatable relative thereto to axially move said adjustment member alongthe length of said hollow body; and means for pivotally supporting saidfirst and second arm means on said adjustment member, for axial movementtherewith along the length of said hollow body, in a manner permittingsaid fist and second arm means to be pivoted to positions in which saidouter end portions thereof are disposed inwardly of the transverselyenlarged outer side section of said refrigerant flow fitting ongenerally opposite sides thereof, and then releasably lock said outerarm means end portions against the enlarged outer side section of saidrefrigerant flow fitting, and forcibly wedge said resilient second endportion of said hollow body into said open outer end of said refrigerantflow fitting, in response to relative axial movement between saidadjustment member and said hollow body.
 2. The adapter fitting of claim1 wherein:said means for pivotally supporting include first and secondbar members extending transversely to said adjustment member and havingcentral portions slidably carried on opposite sides of said adjustmentmember, and means for pivotally connecting inner end portions of saidfirst and second arm means to outer end portions of said bar members onopposite sides of said adjustment member.
 3. The adapter fitting ofclaim 2 wherein:outer end portions of said first and second arm meansare transversely bent, extend generally toward one another, and areconfigured and positionable to be placed behind, and be tightly drawn upagainst, said transversely enlarged outer side portion of saidrefrigerant flow fitting.
 4. The adapter fitting of claim 2 wherein:saidmeans for pivotally connecting inner end portions of said first andsecond arm means to outer end portions of said bar members areadjustable to selectively vary the distances of said outer arm means endportions from said bar members.